Successful unrelated umbilical cord blood transplantation in Lesch-Nyhan syndrome

Lesch-Nyhan syndrome (LNS) is a chronic, progressive neurodevelopmental disorder causing motor and behavioral dysfunction due to decreased synthesis of the enzyme hypoxantine-guanine phosphoribosyltransferase (HPRT). Affected boys have mental retardation, delayed development, extrapyramidal motor disturbances and self-injuring behavior. As hematopoietic stem cell transplantation (HSCT) has been shown to be effective in several neurodevelopmental inborn errors, we hypothesized that it could be favorable in LNS as well. Following a myeloablative conditioning regimen (busulphan 3.2 mg/kg/day for 4 days, cyclophosphamide 60 mg/kg/day for 2 days with ATG Thymoglobin 2.5 mg/kg/day for 4 days) an unrelated umbilical cord blood unit was transfused at the age of 2 years. The graft was a 6/6 HLA-matched at HLA-A, B loci by antigen level, and at DRB1 by allelic level typing. Infused total nucleated cell dose was 3.6 × 10e7 per kilogram body weight. Serum HPRT levels reached normal values by the end of the sixth month post transplant. Slow neurodevelopmental improvement seen during the three-year follow-up and the missing self-injuring behavior can be considered as a proof for the presence of enzyme-competent cells behind the blood–brain barrier.     

Serosurvey of pathogenic hantaviruses among forestry workers in Hungary

Objectives

The aim of the study was to survey the prevalence of human hantavirus infections among forestry workers, who are considered a risk population for contracting the disease. Sera collected from volunteers were tested for antibodies against Dobrava-Belgrade (DOBV) and Puumala (PUUV) viruses.

Material and Methods

For serological analyses, full capsid proteins of DOBV and PUUV viruses were produced in a bacterial expression system, while Ni-resin was used for protein purification. Samples were screened for anti-hantavirus antibodies by ELISA, results were confirmed by Western blot analysis.

Results

A total of 835 samples collected from 750 males and 85 females were tested by indirect ELISA and positive test results were confirmed by Western blot assay. Out of the 45 ELISA-reactive samples, 38 were confirmed by Western blot analysis. The regional distribution of seropositive individuals was as follows: 1.9% (2/107) in the Danube-Tisza Plateau (Great Plains), 3.1% (10/321) in the Southern Transdanubian region, 5.2% (13/248) in the Northern Transdanubian, and 8.2% (13/159) in the North Hungarian Mountains.

Conclusions

Our data show marked geographic differences in seroprevalence of pathogenic hantaviruses within Hungary, indicating elevated exposure to hantavirus infections in some areas.     

Quantitative T2 evaluation at 3.0T compared to morphological grading of the lumbar intervertebral disc: a standardized evaluation approach in patients with low back pain

Background

The purpose of our investigation was to compare quantitative T2 relaxation time measurement evaluation of lumbar intervertebral discs with morphological grading in young to middle-aged patients with low back pain, using a standardized region-of-interest evaluation approach.

Patients and methods

Three hundred thirty lumbar discs from 66 patients (mean age, 39 years) with low back pain were examined on a 3.0 T MR unit. Sagittal T1-FSE, sagittal, coronal, and axial T2-weighted FSE for morphological MRI, as well as a multi-echo spin-echo sequence for T2 mapping, were performed. Morphologically, all discs were classified according to Pfirrmann et al. Equally sized rectangular regions of interest (ROIs) for the annulus fibrosus were selected anteriorly and posteriorly in the outermost 20% of the disc. The space between was defined as the nucleus pulposus. To assess the reproducibility of this evaluation, inter- and intraobserver statistics were performed.

Results

The Pfirrmann scoring of 330 discs showed the following results: grade I: six discs (1.8%); grade II: 189 (57.3%); grade III: 96 (29.1%); grade IV: 38 (11.5%); and grade V: one (0.3%). The mean T2 values (in milliseconds) for the anterior and the posterior annulus, and the nucleus pulposus for the respective Pfirrmann groups were: I: 57/30/239; II: 44/67/129; III: 42/51/82; and IV: 42/44/56. The nucleus pulposus T2 values showed a stepwise decrease from Pfirrmann grade I to IV. The posterior annulus showed the highest T2 values in Pfirrmann group II, while the anterior annulus showed relatively constant T2 values in all Pfirrmann groups. The inter- and intraobserver analysis yielded intraclass correlation coefficients (ICC) for average measures in a range from 0.82 (anterior annulus) to 0.99 (nucleus).

Conclusions

Our standardized method of region-specific quantitative T2 relaxation time evaluation seems to be able to characterize different degrees of disc degeneration quantitatively. The reproducibility of our ROI measurements is sufficient to encourage the use of this method in future investigations, particularly for longitudinal studies.     

Divergent peripheral effects of pituitary adenylate cyclase-activating polypeptide-38 on nociception in rats and mice

Pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38) and its receptors have been shown in the spinal dorsal horn, on capsaicin-sensitive sensory neurons and inflammatory cells. The role of PACAP in central pain transmission is controversial, and no data are available on its function in peripheral nociception. Therefore, the aim of the present study was to analyze the effects of locally or systemically administered PACAP-38 on nocifensive behaviors, inflammatory/neuropathic hyperalgesia and afferent firing. Intraplantar PACAP-38 (0.2 nmol) injection inhibited carrageenan-evoked inflammatory mechanical allodynia, mild heat injury-induced thermal hyperalgesia, as well as nocifensive behaviors in the early and late phases of the formalin test in rats. However, the above dose did not alter basal mechanical or heat thresholds. In mice, PACAP-38 (0.2 nmol/kg s.c.) significantly diminished acetic acid-induced abdominal contractions, but exerted no effect on sciatic nerve ligation-induced neuropathic mechanical hyperalgesia. In contrast, local PACAP-38 injection markedly increased rotation-induced afferent firing in the inflamed rat knee joint clearly demonstrating a peripheral sensitization in this organ. These actions were blocked by VPAC1/VPAC2 receptor antagonist pretreatment, but were not altered by PAC1 receptor antagonism. This paper presents the first data for the peripheral actions of PACAP-38 on nociceptive transmission mediated by VPAC receptors. These effects seem to be divergent depending on the mechanisms of nociceptor activation and the targets of PACAP actions. In acute somatic and visceral inflammatory pain models, PACAP exerts anti-nociceptive, anti-hyperalgesic and anti-allodynic effects. It has no significant peripheral role in traumatic mononeuropathy, but induces mechanical sensitization of knee joint primary afferents.     

Clinical aspects of Epstein-Barr-virus-associated lymphoproliferative disease

Majority of the Western population is infected with the Epstein-Barr virus. Except for mononucleosis accumulating in adolescents, the infection occurs in a rather symptomless manner. But later on under special circumstances the virus may play an important role, again. As a result of long-lasting and intensive immunosuppression i.e. following transplantation a lymphoproliferation of B cell origin may develop in some patients. The biologic behaviour is often more aggressive than expected by the histological occurrence. Early identification of predisposed patients is an important but difficult task: the disease exhibits a rather heterogeneous phenotype and the grading is problematic by the standard classification criteria of non-Hodgkin malignant lymphomas. Nevertheless the diagnosis and the therapy based on the appropriate pathomechanism can increase the chances of convalescence. This review article discusses the pathomechanism, diagnostic and therapeutic relevance of the posttransplant lymphoproliferative disease.     

Development and characterisation of a monoclonal antibody family against aquaporin 1 (AQP1) and aquaporin 4 (AQP4)

Recent studies have discovered the existence of water-channel molecules, the so called aquaporins (AQP) presumably involved in active, ATP dependent water transport between the intracellular and extracellular compartments. Both genetic and protein sequences and structures of the AQPs are known and crystallographic analyses of some members of the AQP family have been performed. Specific antibodies are required to examine their histological locations and analyse their roles in physiological and pathological pathways of water transportation and osmotic regulation. Until recently some polyclonal antibodies have been developed against certain members of the AQP family. However, to date highly specific monoclonal antibodies against aquaporins do not exist. We have developed a monoclonal antibody family against the aquaporin 1 (AQP1) and aquaporin 4 (AQP4) molecules. Well-conserved epitop sequences of AQP1 and AQP4 proteins were selected by computer analysis and their synthetic peptide fragments were used as the antigens of immunisation and the following screening. Antibodies were characterised by immunoserological methods (ELISA, dot-blot and immunoblot), flow cytometry and immunohistochemistry of formaldehyde-fixed and paraffin-embedded tissue samples. RT-PCR tests controlled the specificity of the immune reactions. Our monoclonal antibodies recognised AQP1 and AQP4 in all the techniques mentioned above and apparently they are useful both in various quantitative and qualitative measurements of the expressions of AQP1 and AQP4 in several species (human, rat, mouse, invertebrates, even plants). According to preliminary immunohistochemical studies our monoclonal anti-AQP1 and anti-AQP4 antibodies are appropriate tools of patho-morphological examinations on routine formol-paraffin tissue samples.     

Fine-tuning the EBV+ hu-PBL-SCID xenogeneic chimera model usingIn Vivo superinfection

Our purpose was to establish a reproducible xenogeneic chimera model to observe tumors similar to the well-known human posttransplant lymphoproliferative disease (LPD). First we followed the original protocol injecting Epstein-Barr virus positive (EBV+) human peripheral blood lymphocytes (PBL) intraperitoneally into immunodeficient (SCID) mice. Human cells showed T cell phenotype in majority one week after the transfer, whereas one month later a shift towards B cell phenotype was evident according to immunohistochemical and flow cytometric analysis. At this stage the intraperitoneal mass of cells suggested a biologically malignant behaviour infiltrating the liver and the spleen of the host animal. Immunohistochemistry indicated proliferating human lymphatic cells expressing EBV associated proteins and characteristic patterns of invasion within the affected organs. Eventually LPD was lethal to the host animals in 46-67 days. However, the microscopic appearance of experimental LPD was different from the human haemopoietic malignancies: the basic structures of lymphatic organs were preserved and the human T and B cells repopulated the normally T and B dependent areas in mice. The phenotypes of the proliferating cells were human and characteristic for the mature T- and B-lymphocytes. No dominant clone developed during in vitroculturing of the biologically invasive mass of cells removed from the tumor-bearing mice. The results of microscopical, immunological, and flow cytometrical analysis suggested a mature but uncontrolled proliferation of human lymphocytes in SCID mice. The original method for the induction of post-transplant LPD in SCID mice was modified in our further experiments to standardise the experimental technique increasing the efficiency of B cell proliferation and the reducing the number of unspecific factors. Subsequent in vivo EBV superinfection was carried out after the intraperitoneal transfer of a reduced quantity of human PBL from different donors. The same disease developed in our modified chimera model as by the use of original protocol except for some valuable differences. All hosts developed LPD regardless the significantly reduced amount of transplanted PBL and it was lethal in a shorter period of time (41-43 days) compared to the original model. The decreased quantity of transplanted human lymphatic cells was formerly insufficient using the original protocol. Therefore this modified and standardised protocol can lead to a more predictable and reproducible model allowing us to examine fine details of posttransplant lympho-proliferative disease.     

Novel monoclonal antibodies against mouse C3 interfering with complement activation: description of fine specificity and applications to various immunoassays

The role of complement proteins in various pathophysiological settings has been studied primarily using mouse models of disease. However, the specific contribution of C3-derived fragments to these biologic processes has not been addressed in a rigorous manner because of a lack of antibodies that can selectively recognize mouse C3 or any of its degradation fragments. Here we report the generation and characterization of a panel of rat monoclonal antibodies reacting with mouse C3 and its degradation products. We describe their performance in various immunological assays such as ELISA, Western blotting, flow cytometry and immunohistochemistry. Of all the antibodies generated, one selectively recognized the C3a anaphylatoxin, and all other reacted with C3c. Furthermore, two monoclonal antibodies preferentially reacted with the cleaved C3 fragments C3b/iC3b/C3c but not native C3. Except for the one recognizing C3a, all antibodies were suitable for detecting C3 deposited on cells and tissues, two effectively inhibited the hemolytic activity of mouse complement and one enhanced C3-deposition to the cell membrane. These novel monoclonal antibodies may serve as useful reagents for elucidating functions mediated by C3-derived fragments in various pathophysiological conditions.     

Long-term NR2B expression in the cerebellum alters granule cell development and leads to NR2A down-regulation and motor deficits

N-methyl-D-aspartate receptor (NMDAR) composition in granule cells changes characteristically during cerebellar development. To analyze the importance of NR2B replacement by NR2C and NR2A subunits until the end of the first month of age, we generated mice with lasting NR2B expression but deficiency for NR2C (NR2C-2B mice). Mutant phenotype was different from NR2C knock-out mice as loss of granule cells and morphological changes in NR2C/2B cerebellar architecture were already evident from the second postnatal week. Increased NR2B subunit levels led also to a gradual down-regulation of cerebellar NR2A levels, preceding the development of motor impairment in adult animals. Therefore, cerebellar NR2A is important for proper motor coordination and cannot be replaced by long-term expression of NR2B. Consequently, the physiological exchange of NMDA receptor subunits during cerebellar granule cell maturation is important for accurate postnatal development and function.